The present invention relates to a reflector produced by consecutive injections of thermoplastic materials, especially for headlamps of automobile vehicles.
For several years it has been proposed to replace metallic reflectors attached in a support by reflectors of thermoplastic material. This solution offers numerous advantages compared with attached metallic reflectors. Reflectors of thermoplastic material can be moulded in one single piece with the support, with comparatively reduced industrial means. They are lighter, can assume different and varied forms, and in general they offer better resistance to atmospheric and chemical agents.
However in general they possess drawbacks connected with the function of the reflector. In fact the reflecting surface must be as fine as possible, while the reflector with the support of which generally it is a part, must have good mechanical strength and especially excellent thermal resistance. In fact the temperature generated by the lamps placed in the vicinity of the reflecting surface must produce only slight deformation of the latter, compatible with the performance required of the reflector. Of course the thermoplastic material must be cheap and easy to mould.
These contradictory qualities have led to the use of reinforced thermoplastic materials the surface condition of which does not permit metallisation in order to obtain a usable reflecting surface. Thus it was necessary to lacquer these materials before metallisation, which increases the cost price and the rejects.